Copper-zinc alloy



. rolled hot.

Patented Sept. 23, 1941 COPPER-ZINC ALLOY Wolf Johannes Miiller andMoritz Niessner,

Vienna, Germany, assignors, by mesne assignments, to AktiengesellschaltDynamit Nobel, Pressburg, Czechoslovakia, a company No Drawing.Application No. 215,856. In Austria 2 Claims.

It is known that gamma-brass, that is to say copper zinc alloys with acopper content of about 31-40%, 1. e. alloys which are characterized bya low copper .content, are more resistant to cor-' rosion than the brassalloys of the alpha. and alpha and beta region with for instance 68-72percent and more of copper, i. e., a higher copper content. Thetechnical employment of gammaalloys poor in copper is howeverimpossible, since these alloys are extremely hard and brittle and areconsequently not machinable.

From such alloys, as is described in our prior Patents No. 2,006,598 and2,006,599 it has been disclosed that it is possible, by the addition ofa few percent of a metal soluble in gamma-brass or alloyable therewith,such as nickel or, with more advantage cobalt, preferably by asimultaneous additionof nickel and cobalt, to obtain allow, whichpossess the good resistance to corrosion of gamma-alloys poor in copper,but are also capable of being worked up, that is to say can be treatedwith machine tools and can also be Such alloys with an addition ofapproximately 3-12% of cobalt, nickel or the like individually or inmixture, that is to say for. instance pure copper-zinc alloys with aminimum content of nickel of approximately 7-8% or of cobalt ofapproximately 6% have extremely good technical properties, and whencobalt and nickel are used simultaneously it is possible with a muchsmaller cobalt content to obtain the same effects as with the use ofcobalt alone. Consequently alloys that are deficient in copper, eventhose most deficient, can be made utilisable for industrial purposes oras constructional material for the production of articles, if thecopper-zinc alloys are alloyed with copper, nickel or the likeindividually or in mixture. The present invention is based on theascertained fact that such copper zinc alloys, containing between 30 and45% of copper and between 3 and 12% of cobalt and/or nickel, can havetheir properties substantially improved when containing also between 4and 15% 01' manganese and at least a small but effective amount of oneof the metals of the following group:

Percent Ir n up to 1.8 Aluminium up to 1.5 Silver upto 2.0 Chr mi m upto 3.0 Tin up to 2.0 Lead up to 0.3 Selenium up to 0.6

June 25, 1938, Serial June 21, 1934 but in no greater amounts than aresoluble in the solid solution and the zinc constituting substantiallytheremainder.

It has been ascertained'that such alloys are suitable for cold working,including cold rolling, pressing and drawing and atthe same time have ahigh resistance to corrosion.

In carrying out the invention, the manganese content should be smallerin the case of alloys of higher copper content than in the case ofalloys of lower copper content. The higher themanganese content the moresuitable is the alloy for cold working a rising addition of manganese upto about 10% leading to an approximately proportional improvement in thecold working properties.

By the addition of the metals of the group: iron, aluminium, silver,chromium, tin, lead, selenium and tellurium the workability in the cold,the color and other properties of the alloys are favourably influencedas compared with such alloys containing only copper, zinc, nickel and/orcobalt and manganese as are subject of our c0- pending application Ser.No. 148,506 filed June 16, 1937, from which the present application isdivided out. 7

Thus an, enhanced workability in the cold can be imparted to the alloysof the invention, by

so of the elements iron,

the addition of suitable amounts of one or more lead, tin, selenium andtellurium within the limits hereinbefore set forth while their corrosionresistance can be enhanced .by the addition of one or more of the metalsaluminium, chromium and tin without the limits hereinbefore set forth.

\ It is easy to ascertain empirically, the amount of each element thatwill produce the most favourable eflect.

A suitable alloy in accordance with the inven- 40 tion is one containingbetween 30 and of copper, between 3 and 12% of cobalt and/or nickel,between 4 and 15% of manganese and between 0.5 and 1.5% of iron.

The addition of up to 0.3% of phosphorus to 45 the hereindescribedalloys is advantageous since it very considerably improves the finenessof structure of the alloys.

By means of the additions according to the in up to 0.6 be convertedinto a state corresponding to gamma brass and rendered suitable forapplications, such as cold rolling-or drawing, from which they areotherwise excluded on account of their copper content. I v

The i'ollowing is a typical example of an alloy according to theinvention:

Percent Cu 36 Ni j 6 I 2 Mn 10 F 1.2 Zn Remainder What weclaim is: l. Acorrosion-resistant copper-zinc alloy which is workable in the coldstate, comprising copper in an amount of 30% to 45%, at least one metalof the group cobalt and nickel in an amount 01' 3% to 12%, manganese inan amount or 4% to of 3% to 12%, manganese in an amount or 4% 15%, iron0.5% to 1.5%, and aluminum which 20 to 15%, iron 0.5% to 1.5% andaluminum in a small but effective amount which is capable of increasingthe corrosion of resistance of the al- 10y, said aluminum being presentup to 1.5%,

the zinc constituting substantially all the remainder.

WOLF JOHANNES MORITZ NIESSNER.

Patent No. 2,256,788-

It is hereby certified of the above numbered line 57, for column, line514., for

Patent should be rea form to the record 0 and iealed column,

Signed (Seal) CERTIFICATE OF CORRECTION.

September 25, 19141.

WOLF JOHANNES M L ILLER, ET AL.

that error appears in the printed specification Page 1, first patentrequiring correction as follows;

second the word "copper" read -cobalt; same page,

"without" read -within-; and that the said Letters d with thiscorrection therein that the same may conf the case in the Patent Office.this Ltth day of November, A. D. 191d.

Henry Van Arsdale, Acting Commissioner of Patents.

